In Forrester's evaluation of the emerging market for software-as-a-service (SaaS) marketplaces, we identified the eight most significant providers in the category — Adobe, ADP, Alibaba, Amazon Web Services (AWS), Google, Microsoft, Salesforce, and ServiceNow — and evaluated them. We couldn't include SAP this year, as the vendor was in the process of launching a new online marketplace that wasn't ready by our evaluation date. This report details our findings about how well each vendor scored against 10 criteria and where they stand in relation to each other. Application development and delivery (AD&D) professionals can use this review to select the right partner for their SaaS marketplace needs.